scholarly journals Chk1 and p21 Cooperate to Prevent Apoptosis during DNA Replication Fork Stress

2006 ◽  
Vol 17 (1) ◽  
pp. 402-412 ◽  
Author(s):  
Rene Rodriguez ◽  
Mark Meuth
Keyword(s):  
Dna Replication ◽  
Cellular Response ◽  
Replication Fork ◽  
Replication Stress ◽  
S Phase ◽  
Cell Cycle Checkpoints ◽  
Primary Role ◽  
Excess Thymidine ◽  
Dna Replication Stress ◽  
Interfering Rna

Cells respond to DNA replication stress by triggering cell cycle checkpoints, repair, or death. To understand the role of the DNA damage response pathways in determining whether cells survive replication stress or become committed to death, we examined the effect of loss of these pathways on cellular response to agents that slow or arrest DNA synthesis. We show that replication inhibitors such as excess thymidine, hydroxyurea, and camptothecin are normally poor inducers of apoptosis. However, these agents become potent inducers of death in S-phase cells upon small interfering RNA-mediated depletion of the checkpoint kinase Chk1. This death response is independent of p53 and Chk2. p21-deficient cells, on the other hand, produce a more robust apoptotic response upon Chk1 depletion. p21 is normally induced only late after thymidine treatment. In Chk1-depleted cells p21 induction occurs earlier and does not require p53. Thus, Chk1 plays a primary role in the protection of cells from death induced by replication fork stress, whereas p21 mediates through its role in regulating entry into S phase. These findings are of potential importance to cancer therapy because we demonstrate that the efficacy of clinically relevant agents can be enhanced by manipulation of these signaling pathways.

Abstract LB-164: DNA ligase IV modulates the cellular response to DNA replication stress

2016 ◽  
Author(s):  
Grace Hooks ◽  
Yasmin Anchondo ◽  
Neelam Sharma ◽  
Jac Nickoloff ◽  
Amanda Ashley
Keyword(s):  
Dna Replication ◽  
Cellular Response ◽  
Replication Stress ◽  
Dna Ligase ◽  
Dna Ligase Iv ◽  
Ligase Iv ◽  
Dna Replication Stress

scholarly journals A Mutant Allele of MRE11 Found in Mismatch Repair-deficient Tumor Cells Suppresses the Cellular Response to DNA Replication Fork Stress in a Dominant Negative Manner

2008 ◽  
Vol 19 (4) ◽  
pp. 1693-1705 ◽  
Author(s):  
Qin Wen ◽  
Jennifer Scorah ◽  
Geraldine Phear ◽  
Gary Rodgers ◽  
Sheila Rodgers ◽  
...  
Keyword(s):  
Dna Replication ◽  
Mutant Allele ◽  
Cellular Response ◽  
Replication Fork ◽  
Protein A ◽  
Cancer Cell Line ◽  
Replication Stress ◽  
Dominant Negative ◽  
Mutant Protein ◽  
In Cells

The interaction of ataxia-telangiectasia mutated (ATM) and the Mre11/Rad50/Nbs1 (MRN) complex is critical for the response of cells to DNA double-strand breaks; however, little is known of the role of these proteins in response to DNA replication stress. Here, we report a mutant allele of MRE11 found in a colon cancer cell line that sensitizes cells to agents causing replication fork stress. The mutant Mre11 weakly interacts with Rad50 relative to wild type and shows little affinity for Nbs1. The mutant protein lacks 3′-5′ exonuclease activity as a result of loss of part of the conserved nuclease domain; however, it retains binding affinity for single-stranded DNA (ssDNA), double-stranded DNA with a 3′ single-strand overhang, and fork-like structures containing ssDNA regions. In cells, the mutant protein shows a time- and dose-dependent accumulation in chromatin after thymidine treatment that corresponds with increased recruitment and hyperphosphorylation of replication protein A. ATM autophosphorylation, Mre11 foci, and thymidine-induced homologous recombination are suppressed in cells expressing the mutant allele. Together, our results suggest that the mutant Mre11 suppresses the cellular response to replication stress by binding to ssDNA regions at disrupted forks and impeding replication restart in a dominant negative manner.

scholarly journals DNA replication stress induced by trifluridine determines tumor cell fate according to p53 status

2019 ◽  
Author(s):  
Yuki Kataoka ◽  
Makoto Iimori ◽  
Ryo Fujisawa ◽  
Tomomi Morikawa-Ichinose ◽  
Shinichiro Niimi ◽  
...  
Keyword(s):  
Dna Replication ◽  
Tumor Cell ◽  
Tumor Cells ◽  
Cell Fate ◽  
Replication Fork ◽  
Apoptotic Cell ◽  
Replication Stress ◽  
Dna Replication Stress ◽  
P53 Status ◽  
Fork Stalling

ABSTRACTDNA replication stress is a predominant cause of genome instability, a driver of tumorigenesis and malignant progression. Nucleoside analog-type chemotherapeutic drugs introduce DNA damage and exacerbate DNA replication stress in tumor cells. However, the mechanisms underlying tumor cytotoxicity triggered by the drugs are not fully understood. Here, we show that the fluorinated thymidine analog trifluridine (FTD), an active component of the chemotherapeutic drug trifluridine/tipiracil, delayed DNA synthesis by human replicative DNA polymerases. FTD acted as an inefficient deoxyribonucleotide triphosphate source (FTD triphosphate) and as an obstacle base (trifluorothymine) in the template DNA strand. At the cellular level, FTD decreased thymidine triphosphate in the dNTP pool and induced FTD triphosphate accumulation, resulting in replication fork stalling caused by FTD incorporation into DNA. DNA lesions involving single-stranded DNA were generated as a result of replication fork stalling, and the p53-p21 pathway was activated. Although FTD suppressed tumor cell growth irrespective of p53 status, tumor cell fate diverged at the G2/M phase transition according to p53 status; tumor cells with wild-type p53 underwent cellular senescence via mitosis skip, whereas tumor cells that lost wild-type p53 underwent apoptotic cell death via aberrant late mitosis with severely impaired separation of sister chromatids. These results suggest that DNA replication stress induced by a nucleoside analog-type chemotherapeutic drug triggers tumor cytotoxicity by determining tumor cell fate according to p53 status.SignificanceThis study identified a unique type of DNA replication stress induced by trifluridine, which directs tumor cell fate either toward cellular senescence or apoptotic cell death according to p53 status.

scholarly journals MRE11-RAD50-NBS1 activates Fanconi Anemia R-loop suppression at transcription-replication conflicts

2018 ◽  
Author(s):  
Emily Yun-chia Chang ◽  
James P. Wells ◽  
Shu-Huei Tsai ◽  
Yan Coulombe ◽  
Yujia A. Chan ◽  
...  
Keyword(s):  
Dna Replication ◽  
Fanconi Anemia ◽  
Replication Fork ◽  
Genome Instability ◽  
Human Cancer ◽  
Replication Stress ◽  
Maintenance Factors ◽  
Genome Wide ◽  
A Genome ◽  
Dna Replication Stress

SUMMARYEctopic R-loop accumulation causes DNA replication stress and genome instability. To avoid these outcomes, cells possess a range of anti-R-loop mechanisms, including RNaseH that degrades the RNA moiety in R-loops. To comprehensively identify anti-R-loop mechanisms, we performed a genome-wide trigenic interaction screen in yeast lacking RNH1 and RNH201. We identified >100 genes critical for fitness in the absence of RNaseH, which were enriched for DNA replication fork maintenance factors such as RAD50. We show in yeast and human cells that R-loops accumulate during RAD50 depletion. In human cancer cell models, we find that RAD50 and its partners in the MRE11-RAD50-NBS1 complex regulate R-loop-associated DNA damage and replication stress. We show that a non-nucleolytic function of MRE11 is important for R-loop suppression via activation of PCNA-ubiquitination by RAD18 and recruiting anti-R-loop helicases in the Fanconi Anemia pathway. This work establishes a novel role for MRE11-RAD50-NBS1 in directing tolerance mechanisms of transcription-replication conflicts.

scholarly journals Protein phosphatase 2A (PP2A) promotes anaphase entry after DNA replication stress in budding yeast

2021 ◽  
Author(s):  
Cory Haluska ◽  
Fengzhi Jin ◽  
Yanchang Wang
Keyword(s):  
Cell Cycle ◽  
Dna Replication ◽  
Dna Synthesis ◽  
Protein Phosphatase ◽  
Budding Yeast ◽  
Replication Stress ◽  
S Phase ◽  
Viability Loss ◽  
Phosphatase 2A ◽  
Dna Replication Stress

DNA replication stress activates the S-phase checkpoint that arrests the cell cycle, but it is poorly understood how cells recover from this arrest. Cyclin-dependent kinase (CDK) and Protein Phosphatase 2A (PP2A) are key cell cycle regulators, and Cdc55 is a regulatory subunit of PP2A in budding yeast. We found that yeast cells lacking functional PP2ACdc55 showed slow growth in the presence of hydroxyurea (HU), a DNA synthesis inhibitor, without obvious viability loss. Moreover, PP2A mutants exhibited delayed anaphase entry and sustained levels of anaphase inhibitor Pds1 after HU treatment. A DNA damage checkpoint Chk1 phosphorylates and stabilizes Pds1. We showed that chk1Δ and mutation of the Chk1 phosphorylation sites in Pds1 largely restored efficient anaphase entry in PP2A mutants after HU treatment. In addition, deletion of SWE1 that encodes the inhibitory kinase for CDK or mutation of the Swe1 phosphorylation site in CDK ( cdc28F19) also suppressed the anaphase entry delay in PP2A mutants after HU treatment. Our genetic data suggest that Swe1/CDK acts upstream of Pds1. Surprisingly, cdc55Δ showed significant suppression to the viability loss of S-phase checkpoint mutants during DNA synthesis block. Together, our results uncover a PP2A-Swe1-CDK-Chk1-Pds1 axis that promotes recovery from DNA replication stress.

scholarly journals Managing Single-Stranded DNA during Replication Stress in Fission Yeast

2021 ◽  
Author(s):  
Sarah A. Sabatinos ◽  
Susan L. Forsburg
Keyword(s):  
Cellular Response ◽  
Replication Fork ◽  
Genome Instability ◽  
Replication Stress ◽  
S Phase ◽  
Single Stranded Dna ◽  
Replication Checkpoint ◽  
Primary Signal ◽  
Fork Stalling ◽  
Chromosome Integrity

Replication fork stalling generates a variety of responses, most of which cause an increase in single-stranded DNA. ssDNA is a primary signal of replication distress that activates cellular checkpoints. It is also a potential source of genome instability and a substrate for mutation and recombination. Therefore, managing ssDNA levels is crucial to chromosome integrity. Limited ssDNA accumulation occurs in wild-type cells under stress. In contrast, cells lacking the replication checkpoint cannot arrest forks properly and accumulate large amounts of ssDNA. This likely occurs when the replication fork polymerase and helicase units are uncoupled. Some cells with mutations in the replication helicase (mcm-ts) mimic checkpoint-deficient cells, and accumulate extensive areas of ssDNA to trigger the G2-checkpoint. Another category of helicase mutant (mcm4-degron) causes fork stalling in early S-phase due to immediate loss of helicase function. Intriguingly, cells realize that ssDNA is present, but fail to detect that they accumulate ssDNA, and continue to divide. Thus, the cellular response to replication stalling depends on checkpoint activity and the time that replication stress occurs in S-phase. In this review we describe the signs, signals, and symptoms of replication arrest from an ssDNA perspective. We explore the possible mechanisms for these effects. We also advise the need for caution when detecting and interpreting data related to the accumulation of ssDNA.

scholarly journals Chromatin as a Platform for Modulating the Replication Stress Response

Genes ◽  
2018 ◽  
Vol 9 (12) ◽  
pp. 622 ◽  
Author(s):  
Louis-Alexandre Fournier ◽  
Arun Kumar ◽  
Peter Stirling
Keyword(s):  
Dna Replication ◽  
Stress Response ◽  
Replication Fork ◽  
Replication Stress ◽  
Genome Maintenance ◽  
Post Translational Modifications ◽  
Nucleosome Dynamics ◽  
Dna Replication Stress ◽  
Eukaryotic Dna ◽  
Fork Stalling

Eukaryotic DNA replication occurs in the context of chromatin. Recent years have seen major advances in our understanding of histone supply, histone recycling and nascent histone incorporation during replication. Furthermore, much is now known about the roles of histone remodellers and post-translational modifications in replication. It has also become clear that nucleosome dynamics during replication play critical roles in genome maintenance and that chromatin modifiers are important for preventing DNA replication stress. An understanding of how cells deploy specific nucleosome modifiers, chaperones and remodellers directly at sites of replication fork stalling has been building more slowly. Here we will specifically discuss recent advances in understanding how chromatin composition contribute to replication fork stability and restart.

scholarly journals DNA replication stress in CHK1-depleted tumour cells triggers premature (S-phase) mitosis through inappropriate activation of Aurora kinase B

2014 ◽  
Vol 5 (5) ◽  
pp. e1253-e1253 ◽  
Author(s):  
P Zuazua-Villar ◽  
R Rodriguez ◽  
M E Gagou ◽  
P A Eyers ◽  
M Meuth
Keyword(s):  
Dna Replication ◽  
Replication Stress ◽  
Aurora Kinase ◽  
S Phase ◽  
Tumour Cells ◽  
Aurora Kinase B ◽  
Dna Replication Stress

scholarly journals A role of the mitotic spindle checkpoint in the cellular response to DNA replication stress

2006 ◽  
Vol 99 (3) ◽  
pp. 759-769 ◽  
Author(s):  
Anette Duensing ◽  
Xiaoyi Teng ◽  
Ying Liu ◽  
Michelle Tseng ◽  
Nicole Spardy ◽  
...  
Keyword(s):  
Dna Replication ◽  
Mitotic Spindle ◽  
Cellular Response ◽  
Spindle Checkpoint ◽  
Replication Stress ◽  
Mitotic Spindle Checkpoint ◽  
Dna Replication Stress
Sign in / Sign up

Export Citation Format

Share Document